SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

RGClark · 2023-03-09 10:07:24

Updated discussion of the topic:

SuperHeavy+Starship have the thermal energy of the Hiroshima bomb. UPDATED, 3/8/2023.
https://exoscientist.blogspot.com/2023/ … nergy.html

Key Points.

1.)While the explosive force of the SuperHeavy/Starship (SH/ST) is not likely to reach that of its full thermal content of 13.3 kilotons of TNT, comparable to the Hiroshima bomb, it is still likely to be in the range of 3 to 5 kilotons of TNT.

2.)The Halifax and Texas City disasters of comparable explosive force suggests damage can extend kilometers away.

3.)The hazard or exclusion zones of only 2 miles, 3 km, for SH/ST is likely inadequate based on the Halifax and Texas City disasters.

4.)SpaceX ignored FAA warnings not to launch SN8 due to weather conditions exacerbating the effects of a possible blast wave from an explosion.

5.)The Starship SN11 explosion in midair may have been a BLEVE, which introduces an additional detonation mode for cryogenic fuels.

6.)At least one Raptor leaked methane and caught fire on multiple test flights of the Starship.

7.)Since the SuperHeavy static test lasted little more than 5 seconds, a strong possibility exists that multiple engines will fail during a full burn of an actual flight.

Recommendations.

1.)It should be revealed to the public the SH/ST has the thermal energy content of the Hiroshima bomb.

2.)Experts on launch vehicle explosions and fuel-air detonations should present a report to the public explaining what the likely explosive force would be if the vehicle exploded.

3.)SpaceX should not be granted a launch license for the SH/ST until SpaceX constructs a separate engine test stand sufficient to test all 33 Superheavy engines at the same time at full power and at full flight duration, and until such tests complete successfully for multiple tests.

Robert Clark

Last edited by RGClark (2023-03-09 10:08:55)

GW Johnson · 2023-03-09 12:38:59

The explosion hazard is one of 2 reasons Von Braun's larger designs (the "Nova" configurations) were never built and flown at Cape Canaveral. Lethal noise levels was the other.

The Saturn-5 had a bit over half the explosive potential as SS/SH. That puts it about 1-2 KT worth of likely explosion power. The 3 miles NASA had at Canaveral was barely enough not to cause considerable harm and injury from the noise, as well as from on-the-pad blast wave and thrown-shrapnel effects.

What nobody really took into account was thrown shrapnel from an explosion way up the air. The more powerful the explosion, the further it can throw pieces, and bigger, too! A 10 ton anchor got thrown 5 miles at Texas City. The SS that exploded in midair threw small pieces that landed at the Brownsville city limits, 5 miles away (that just SS, not SH!!!). SS has ~1200 metric tons of propellants when fully loaded. SH has ~ 3400 m.tons. Together, that's 5600 tons. Saturn 5 was about 3500 tons.

These effects and risks are quite real, and Bob is quite right to point them out. Between these real risks and Musk aggravating the bureaucrats with his big mouth on twitter, I'm not surprised the first SH launch has been delayed for some 2 years now, over permitting, and largely due to "environmental effects", which is code words for explosions, fires, noise, and shrapnel.

What SpaceX originally wanted to do was fly SS/SH a few times from Boca Chica, to figure out what the launch infrastructure really was. Then move to an offshore platform to truly mitigate the risks. That won't happen now. It should probably never have been allowed to happen that way, due the very risks we are talking about here.

You have to remember that SS/SH is about as big as the smaller "Nova" configurations, which NASA deemed too dangerous to fire at Canaveral, given a 3-mile radius available. Given that history, why should anyone be surprised that NASA is worried about losing a pad if SS/SH launches at Canaveral, or that the FAA is reluctant to grant a license for SS/SH to fly at Boca Chica?

GW

Last edited by GW Johnson (2023-03-09 12:40:55)

kbd512 · 2023-03-09 14:27:02

GW,

It would be great if someone from FAA would just say those things out loud. Just tell SpaceX that their rocket is too big and potentially dangerous to fly from Boca Chica, because it can kill things from miles away if it explodes, or even if everything goes perfectly. No need to go through years of screwing around to get right to the point. Regardless of what someone in the government thinks of Elon Musk, that was always the correct course of action. The fact that the people in the government can't be forthright about something that simple, which is a valid concern, is appalling.

Someone could just say something like, "Hey buddy, your rocket is so big and powerful, it's a mini-nuke". You need to keep it way the hell away from everything when you light that candle." If this was me and I was still in the government, then regardless of what I thought of Elon Musk, this is what I'd tell SpaceX. They have an iron-clad reason to deny the launch permit (you can't set off nukes, not even small ones, over populated areas, intentional or otherwise).

What this affair really demonstrates is that people in our federal government can't behave like grown adults if they don't like someone. The proper role of government is not to waste time and money, which is ultimately our time and money since we pay their salaries, pursuing revenge against people they don't like. That is inexcusably childish behavior, plain and simple.

RGClark · 2023-03-14 10:11:09

Not reassuring either that whenever Elon or Gwen Shotwell talk about the Starship test launch they always bring up the chances it might explode:

Elon Musk hints Starship rocket may explode on first orbital launch, predicting 50% chance of success and 'guaranteeing excitement'
Marianne Guenot and Morgan McFall-Johnsen Mar 13, 2023, 10:14 PM
https://www.businessinsider.com/elon-mu … ion-2023-3

I discussed before my opinion on this: SpaceX should have taken a graduated approach to superheavy lift: first make a smaller two-stage to orbit vehicle with Starship as the booster with it’s own smaller upper stage. This could have taken over the role of the Falcon 9 and even Falcon Heavy, since it would have comparable propellant load as the Falcon Heavy.

Then when you have many successful launches for this smaller TSTO, then make a superheavy lift extension using triple-cores a la the Falcon Heavy. Remember the Falcon 9 flew over 100 times before the triple-cored Falcon Heavy based on it flew.

You would then have many successful flights under your belt with the smaller Starship-based TSTO before you attempted a launch of the larger rocket 3 times as big. The larger superheavy lift rocket wouldn’t even have to be manrated. You could launch crews on the smaller Starship-based TSTO, and just use the larger triple-cored craft to deliver heavy cargo or interplanetary habitats to orbit:

Monday, February 27, 2023
The Missed Lesson of the Falcon Heavy.
https://exoscientist.blogspot.com/2023/ … heavy.html

Robert Clark

RobertDyck · 2023-03-14 11:36:08

kbd512, Government is appalling. Period. That's a major reason so many people want to move to Mars.

I disagree with comparing SH/SS to a nuke, Heroshima or otherwise. Comparing to the Halifax disaster is fair. I'm not familiar with the Texas City disaster. The largest rocket to explode was the Soviet N1. It failed in 4 test launches, 1969 - 1972. It used RP-1/LOX, not any toxic propellants, so is very comparable. With 30 engines on the first stage, it was very comparable.

According to Wikipedia, the first failure of N1 resulted in engine shutdown. It fell and hit the ground. Explosion resulted in fragments found 52km (32 miles) from the launch pad. Note that's NOT 52km from the impact site.

Second launch attempt resulted in engine shutdown, it leaned over 45° and fell back to the launch pad. Explosion shattered windows across the launch complex and threw debris 10km (6 miles) from the centre of the explosion.

Third launch attempt resulted in interstage between 2nd & 3rd stages twisting apart. Upper stages impacted 7km (4 miles) from the launch complex. 1st & 2nd stages impacted 15km (9 miles) from the launch complex and blasting a 15 metre deep (50 foot) crater in the steppe. Boca Chica is on the coast, any significant distance downrange will be in the Gulf.

Fourth launch attempt: 1st stage started to break up just 15 seconds from scheduled first stage separation. 2nd and upper stages were ejected and crashed into the steppe.

Launch escape system activated successfully for 1st, 2nd & 4th launch attempts. 3rd attempt had a dummy payload, no launch escape system.

RobertDyck · 2023-03-14 11:41:28

With all of these launch failures, fuel and oxidizer did not mix with 100% efficiency. Vehicle failure resulted in just a fraction of the theoretical thermal energy release.

kbd512 · 2023-03-14 12:42:48

RobertDyck,

You have to understand that RGClark has an agenda he wants to pursue. He wants to see SpaceX pursue his SSTO project, which will probably never happen, regardless of any launch failures. However, to RGClark's point, "All the children say, We don't need another Heroshima. We don't need to see a second Sun on the way home." Apologies to Tina Turner in advance. Sorry, I couldn't resist.

If SpaceX did 10 full duration burn test of the Starship Super Heavy and had no failures, rest assured that RGClark would raise another alarm. He's trying to draw attention to what he wants. There's nothing wrong with that, but if he's so dead set on doing this then he can build his own multi-billion dollar space launch services company from the ground-up. Nobody is stopping RGClark from doing that, but him. That requires work he considers drudgery or beneath him, which is why SpaceX is doing what Elon Musk wants, rather than what RGClark wants.

If everyone involved was totally honest about this situation, SpaceX would need to use that offshore oil platform to launch their giant rocket, the FAA and RGClark could huff and puff about it, but if it was more than 15 miles offshore, FAA is no longer the regulatory body governing what SpaceX can or can't launch. So long as the rocket doesn't enter American airspace, they have no more ability to manipulate something they disagree with, reasons unimportant.

If FAA wanted to gain some credibility as a governing body after the Boeing 737 MAX debacle, they could be straight-up and honest with SpaceX and the general public by telling SpaceX that they're not launching something so powerful from Boca Chica because it can kill people far outside the launch area, owing to how powerful their rocket is- far more powerful than a Saturn V.

While we're flapping our gums online, SpaceX has built an actual moon rocket, mostly on their own dime, but with some help from Uncle Sam to pursue his own space objectives. They have made North American launch services cost-competitive with all foreign solutions. They've done all that for a tiny fraction of the cost of a government-run program, because they're committed to getting the job done.

I actually agree with Bob Clark's assertion that at least 1 totally clean run of all engines for a full burn duration should be completed before the booster leaves the ground. This is a perfectly reasonable ask. I disagree with his diversionary project intended to pursue his own SSTO design, which will not help deliver a fully reusable gigantic moon rocket for NASA to use to return to the moon and finally go to Mars. It could be useful for other things, and could be worth pursuing for other ends, but not for what our space program is intended to achieve- which is exploration of space.

The fear of a giant explosion is perfectly valid. All launches of giant rockets can result in giant explosions. The proper way to address this is to inform SpaceX that they're not launching something that big from Boca Chica, but since they're providing the moon lander rocket for Artemis, Uncle Sam will help them acquire an offshore drilling platform and reconfigure it as a launch pad. The goal here is real measurable progress and accomplishment, not regressing back to ideological dead-ends. Lots of people have tried to make SSTO work at scale. They all failed. We don't need to pursue a repeat of past failures, even if RGClark is the one person out there who could actually make it work. It's a project for another time.

RGClark · 2023-04-11 11:09:33

Further on safety issues of the SpaceX Superheavy/Starship launch:

SuperHeavy+Starship have the thermal energy of the Hiroshima bomb, Page 2: shattered windows and flying shrapnel.
https://exoscientist.blogspot.com/2023/ … nergy.html

Key Points

1.)For both shattered windows and flying shrapnel there has to be a statistical distribution given for the distances these can occur, not just a single number, since at even distances commonly given as "safe" some proportion of these can happen beyond that distance.

2.)The 5 km exclusion zone is almost certainly inadequate for shattered windows and flying shrapnel if there were to be an explosion since there is a high statistical chance both can happen beyond this distance, especially for larger size windows, such as the plate glass windows common in stores, commercial properties, and hotels.

3.)The Mexican border is closer to the launch site than 5 km, making it even more likely shattered windows and shrapnel can reach there in the event of an explosion.

4.)Since Mexican citizens might be harmed, SpaceX might cause an international incident if there were an explosion. Therefore, unlike any launch ever undertaken previously by the U.S, the State Department needs to be informed of the possibility of damage on the other side of the U.S./Mexican border, so they won't be blindsided if it does occur.

Recommendations.

1.)Despite SpaceX's desire to have routine, common launches, because rocket engines operate at such extreme levels of temperature and pressure, they are unlikely ever to have the same reliability of for example jet engines. Then it is unlikely the SuperHeavy/Starship combination will ever be safe enough to launch from the Boca Chica site.

2.)Then SpaceX should consider alternatives. Indeed, they first proposed that the launches would take place 20 miles off-shore because of noise concerns for such a large rocket. The safety concerns in case of an explosion are even more pressing to not allow the launch so close to populated areas.

3.)Another approach SpaceX could take is a triple-core arrangement for their large rocket, a la the Falcon Heavy. They would first make a smaller rocket using the Starship this time as a first stage and a smaller mini-Starship as the upper stage. Note, the Merlin engines flew over 1,000 times on actual missions on the Falcon 9, before the Falcon Heavy even flew.
In contrast, the way things are now SpaceX wants to use the Raptor engine on the largest rocket ever built without the Raptor having flown a single time to actual space. And this for engine that failed or caught on fire multiple times in tests.
When SpaceX wanted to proceed to the triple-core version, because of its size it would still need to be launched off-shore, but judging from the example of the Falcon 9 and Falcon Heavy, the single core will fly many more times than the triple-core version in any case.

Robert Clark

RobertDyck · 2023-04-11 14:30:41

Robert Clark: La Burrita Mexico is roughly 12 km from the launch site. They should be fine. "Faro Bagdad" is a light house, historic site, only 5.4 km so could be at risk. Other than that, there's swamp. A greater risk is to hope debris doesn't hit Boca Chica and Starbase.

Elon Musk said the next thing after Starship will be Starship 2. It will be twice diameter and twice high. That means 4 times hull surface area, but 8 times volume. That means 8 times lift capacity, but inert mass will be 4 times, making it more efficient. I argued that Starship 2 is not safe for the reasons you stated. But Starship should be fine. I believe Starship/Superheavy is the largest practical rocket to launch from Earth's surface. There was a proposal in the 1960s for Sea Dragon, but I doubt that will ever be built. The TV series "For All Mankind" showed Sea Dragon. I don't think it will ever happen, but it was nice to see a Hollywood depiction of Sea Dragon launch.

RGClark · 2023-04-12 10:07:22

Note there is dry land on the other side of Rio Grande, so in Mexico:

I'm assuming Mexican launch spectators will assemble there to watch the launch just as Americans do at the tip of South Padre Island. According to the scale at the bottom right, that's 2.8 miles away.

Robert Clark

RobertDyck · 2023-04-12 19:49:57

In case the FAA is reading this, I can't let that slide. If some observers violate range safety rules, they have no one to blame but themselves.

:Edit: Video bloggers erected remote controlled cameras within the safety zone, but they stayed on the island, out of the danger zone. At least one camera did get damaged. This time they can do the same. Safe zone may be larger, but same principle.

GW Johnson · 2023-04-15 10:10:46

5 km (3 miles) was barely enough for the Saturn-5. Had one of those exploded about that same distance up, shrapnel would have gone outside the exclusion zone. There were densely-packed crowds there to see the launch, 3 miles away. Fortunately, none ever exploded.

Starship/Superheavy is over twice the mass and thrust of a Saturn-5. That just makes the blast wave and the shrapnel quantity and thrown distances bigger. Which is exactly why none of the von Braun "Nova" designs were ever built and flown out of Canaveral. Starship/Superheavy is in the lower end of that class of "Nova" designs.

My own guess for an exclusion zone distance would have have been about 10 miles (16 km), but that's just a guess.

GW

RobertDyck · 2023-04-15 14:26:38

As I said in post #5 above, the only comparable launch-pad explosion was the second launch attempt of the N1 rocket in 1969. The furthest debris was sent 10km (6 miles). Based on that, Brownsville is safe. A light house in Mexico called Faro Bagdad is 3.3 miles away, so safe from fireball or concussion, but anyone present should stay indoors away from any window just in case. No other site in Mexico is in danger. Raptor Roost & LabPadre Lookout are 3.88 miles away, Rocket Ranch Outpost Viewing Complex is 3.95 miles away, and Starship Station is 4 miles. These are specifically for viewing launches, and down the road from each other. The eastern tip of Starbase is 1.6 miles from the orbital launch pad. The southern most house on "Long Island" of Port Isabel is 5.3 miles. South Padre Island is 5 miles. Evacuating a 6 mile radius would be... impractical. I think it's more reasonable to tell people at Starbase and Boca Chica to stay indoors. Tell people at the outlooks that they're at their own risk. If anyone tries to set up a camera on any dry land they can find in the swamp on the Mexican side of Rio Grande, tell them they're at their own risk.

kbd512 · 2023-04-16 11:03:34

SpaceX received FAA approval to launch Starship on Friday afternoon and plans to launch on Monday morning.

RobertDyck · 2023-04-17 07:40:46

YouTube: click for clip

Where's the kaboom? There was supposed to be an Earth shattering kaboom!

tahanson43206 · 2023-04-17 10:28:24

For RobertDyck ... Your post #15 is certainly an interesting way to note that the first flight of the Starship combo was scrubbed!

48 hours delay is predicted in the reports I saw. A frozen valve is reported to have been the cause. Something like that is (it seems to me) the sort of thing that only shows up when a ** real ** launch is intended. I understand the dress rehearsal opportunity continued right up to the last few seconds.

I'm hoping other members will add information to this topic, as it arrives/becomes available.

A countdown like this one will be needed ** every ** time this stack launches. This would appear to be a significant employment opportunity for SpaceX employees as the launch pace picks up.

(th)

RobertDyck · 2023-04-17 15:42:15

Elon Musk tweeted the next launch attempt will be tomorrow morning at 8:20am.

Tom: I posted that because Robert G Clark started this discussion about expectation of catastrophic failure. Obviously that failure didn't happen. Cudos to SpaceX, I expect complete success.

The talking heads described this launch attempt as ending with a "hard landing" in the ocean. I thought they were going to attempt a landing simulation on the ocean.

kbd512 · 2023-04-17 16:01:35

We shouldn't count our rocket parts before the entire flight duration is complete. If the machine survives the entire burn duration and the upper stage reenters successfully, then everything else is a bonus. It seems as if SpaceX is going to deep six the entire rocket, regardless of what else happens. That said, if the flight goes well, tomorrow we'll have 39 Raptor-2 engines with real space flight heritage behind them.

RobertDyck · 2023-04-18 05:49:22

SpaceX is now saying next launch attempt Thursday. SpaceX website says they go live April 20 @ 7:45am.

GW Johnson · 2023-04-18 08:06:24

That they had a glitch that stopped the launch is disappointing.

That they recognized they had a problem, and could deal successfully with it, without blowing up, is very encouraging.

It is sometimes hard to tell what the real plan is, especially with so much second-hand and third-hand information floating around. I thought the booster was to "soft land" in the water, but be allowed to fall over and sink. I thought the Starship was just supposed to crash in belly-flop descent. But one never knows exactly what SpaceX is planning until they execute it. Plans can change.

I think they will be lucky not to explode during first stage ascent, and also lucky to successfully separate stages without a collision, or the second stage propulsion stream fatally damaging the first stage as they separate. If they get past stage separation, the next big bugaboo will be getting the second stage to survive reentry. Both the heat shield integrity, and the aerodynamics and control in hypersonic flight are very serious issues.

All that being said, I hope they succeed.

GW

kbd512 · 2023-04-20 07:43:53

Starship launched and cleared the tower and the booster completed its burn, but failed to separate, so the entire vehicle made the boost-back burn before it was subsequently destroyed by range control.

RobertDyck · 2023-04-20 07:54:18

Well, it did blow'd up. It blow'd up real good! I hope RGClark is satisfied.

Some Raptor engines on the first stage failed. 3 engines failed to light. During flight, 3 more failed. But they did achieve max-Q, and got to where stage separation was supposed to happen. But the upper stage didn't separate. The whole rocket spun end-over-end, possibly the autopilot was trying to initiate boost-back but the second stage was still attached. Looks like they activated autodestruct. :'(

RobertDyck · 2023-04-20 08:35:01

From SCTV: Farm Film Report
They blow'd up real good.

GW Johnson · 2023-04-20 09:06:13

Well, there's a lot we don't know, but it appears to be a stage separation failure that triggered the explosion, one way or another. Stage separation was serious issue that nearly bankrupted them at the outset with Falcon-1. You can bet SpaceX already knows more than they are saying. And if the reports of engines failing are correct, that's a real problem, too. I'm just glad the explosion was far enough away not to endanger people on the ground.

GW

Void · 2023-04-20 10:14:28

I reluctantly intrude. I wanted to say that there may have been a pattern to the engine failures. One was in the center, but many seemed to be towards one side more than the other. I guess there could be a common cause. Junk from the ground impacting? Or propellant feed?

I have wondered why they do not put in the water deluge system yet. Perhaps they want to test the endurance of stage '0'?

As I observed it the 1st stage is said to be unclamped before the engines start, and that it takes about 10 seconds for the engines to throttle up. So, then I have concern that debris is being kicked up into the engines.

I wonder if the side more damaged faced the tower, or something else?

Again, I do not consider myself an expert. This is just what I thought I noticed.

Done.

New Mars Forums

Announcement

#1 2023-03-09 10:07:24

SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#2 2023-03-09 12:38:59

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#3 2023-03-09 14:27:02

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#4 2023-03-14 10:11:09

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#5 2023-03-14 11:36:08

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#6 2023-03-14 11:41:28

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#7 2023-03-14 12:42:48

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#8 2023-04-11 11:09:33

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#9 2023-04-11 14:30:41

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#10 2023-04-12 10:07:22

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#11 2023-04-12 19:49:57

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#12 2023-04-15 10:10:46

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#13 2023-04-15 14:26:38

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#14 2023-04-16 11:03:34

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#15 2023-04-17 07:40:46

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#16 2023-04-17 10:28:24

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#17 2023-04-17 15:42:15

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#18 2023-04-17 16:01:35

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#19 2023-04-18 05:49:22

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#20 2023-04-18 08:06:24

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#21 2023-04-20 07:43:53

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#22 2023-04-20 07:54:18

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#23 2023-04-20 08:35:01

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#24 2023-04-20 09:06:13

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

#25 2023-04-20 10:14:28

Re: SuperHeavy+Starship have the thermal energy of the Hiroshima bomb.

Board footer